[英]Isolate and manage collections CRUD done by signed in User - Firebase and Flutter
[英]Crud app with firebase conncetion (flutter)
我学习 flutter。我是初学者,目前开始使用 firebase 学习 CRUD。
我从这位伟大的绅士的代码中学习
https://github.com/mohamedHassanKa/ProductAppCourse
我是第一次连接firebase,我连接firebase成功了吗? 我得到了这些错误。 有人可以教我如何更正代码吗?
CRUDEModel.dart
import 'dart:async';
import 'package:flutter/material.dart';
import '../../locator.dart';
import '../services/api.dart';
import '../models/productModel.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
class CRUDModel extends ChangeNotifier {
Api _api = locator<Api>();
List<Product> products;
Future<List<Product>> fetchProducts() async {
var result = await _api.getDataCollection();
products = result.documents
.map((doc) => Product.fromMap(doc.data, doc.documentID))
.toList();
return products;
}
Stream<QuerySnapshot> fetchProductsAsStream() {
return _api.streamDataCollection();
}
Future<Product> getProductById(String id) async {
var doc = await _api.getDocumentById(id);
return Product.fromMap(doc.data, doc.documentID) ;
}
Future removeProduct(String id) async{
await _api.removeDocument(id) ;
return ;
}
Future updateProduct(Product data,String id) async{
await _api.updateDocument(data.toJson(), id) ;
return ;
}
Future addProduct(Product data) async{
var result = await _api.addDocument(data.toJson()) ;
return ;
}
错误
lib/core/viewmodels/CRUDModel.dart:16:23: Error: The getter 'documents' isn't defined for the class 'QuerySnapshot<Object>'.
- 'QuerySnapshot' is from 'package:cloud_firestore/cloud_firestore.dart' ('../../Documents/flutter_windows_3.3.4-stable/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-4.1.0/lib/cloud_firestore.dart').
- 'Object' is from 'dart:core'.
Try correcting the name to the name of an existing getter, or defining a getter or field named 'documents'.
products = result.documents
^^^^^^^^^
lib/core/viewmodels/CRUDModel.dart:28:43: Error: The getter 'documentID' isn't defined for the class 'DocumentSnapshot<Object>'.
- 'DocumentSnapshot' is from 'package:cloud_firestore/cloud_firestore.dart' ('../../Documents/flutter_windows_3.3.4-stable/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-4.1.0/lib/cloud_firestore.dart').
- 'Object' is from 'dart:core'.
Try correcting the name to the name of an existing getter, or defining a getter or field named 'documentID'.
return Product.fromMap(doc.data, doc.documentID) ;
^^^^^^^^^^
lib/core/viewmodels/CRUDModel.dart:28:33: Error: The argument type 'Object Function()' can't be assigned to the parameter type 'Map<dynamic, dynamic>'.
- 'Object' is from 'dart:core'.
- 'Map' is from 'dart:core'.
return Product.fromMap(doc.data, doc.documentID) ;
^
lib/core/services/api.dart:5:9: Error: Type 'Firestore' not found.
final Firestore _db = Firestore.instance;
^^^^^^^^^
lib/core/services/api.dart:5:9: Error: 'Firestore' isn't a type.
final Firestore _db = Firestore.instance;
^^^^^^^^^
lib/core/services/api.dart:5:25: Error: Undefined name 'Firestore'.
final Firestore _db = Firestore.instance;
^^^^^^^^^
既然你说你是新人,那么你应该知道这个存储库是 3 年前制作的,并且 Flutter 的 Firebase SDK 发生了很多更新。
使用新版本的 Firebase 服务,就在 Firestore 中,在您的项目中获取它的实例:
Firestore.instance // old
FirebaseFirestore.instance // new
documents
属性被替换为docs
,所以你需要使用这个:
result.documents // old - not working
result.docs // new - will return a List<DocumentSnapshot>
要获取特定文档的Map<String, dynamic>
数据,您需要:
doc.data // old
doc.data() as Map<String, dynamic> new
要获取文档的id
,您应该使用:
doc.documentId // old
doc.id // new
所以基本上你的新迁移代码应该与此类似:
class CRUDModel extends ChangeNotifier {
Api _api = locator<Api>();
List<Product> products;
Future<List<Product>> fetchProducts() async {
QuerySnapshot result = await _api.getDataCollection();
products = result.docs
.map((doc) => Product.fromMap(doc.data() as Map<String, dynamic>, doc.id))
.toList();
return products;
}
Stream<QuerySnapshot> fetchProductsAsStream() {
return _api.streamDataCollection();
}
Future<Product> getProductById(String id) async {
DocumentSnapshot doc = await _api.getDocumentById(id);
return Product.fromMap(doc.data() as Map<String, dynamic>, doc.id) ;
}
Future removeProduct(String id) async{
await _api.removeDocument(id) ;
return ;
}
Future updateProduct(Product data,String id) async{
await _api.updateDocument(data.toJson(), id) ;
return ;
}
Future addProduct(Product data) async{
var result = await _api.addDocument(data.toJson()) ;
return ;
}}
我认为这些更改还不够,您需要使用 Firebase SDK 的新术语/符号进行迁移。
我会说你需要停止关注旧存储库(没有冒犯它的所有者),并寻找一个新项目,或者先关注并阅读 Firebase 的官方文档。
检查这个:
https://firebase.flutter.dev/docs/firestore/overview
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.